2007 ISUZU KB P190 service

Engine Management – V6 – Diagnostics Page 6C1-2–132

Step Action Yes No
7

To avoid damage to the drive axles, support the lower
control arms in the normal horizontal position. Do not
run the vehicle in gear with the wheels hanging down
at full travel.
1 Raise the vehicle and support the drive axles with safety stands. Refer to 0A General Information for the location of jacking and
support points.
2 Connect a fused jumper wire between the ground circuit of the connector and the ground circuit of the VSS.
3 Connect a fused jumper wire between the ignition circuit of the connector and the ignition circuit of the VSS.
4 Using connector test adaptor kit J 35616-A, connect a digital multimeter between the VSS signal circuit and ground.
5 Place the transmission in neutral.
6 Rotate the rear wheels by hand while observing the multimeter.
Does the multimeter indicate greater than 0.15 V AC? Go to Step 10 Go to Step 8
8 Perform the following VSS inspection:
• Inspect the VSS wiring harness for conditions that may induce
electromagnetic interference. Refer to 5.2 Intermittent Fault
Conditions in this Section.
• Inspect the VSS for incorrect installation or incorrect attaching
bolt torque value. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
• Inspect the VSS sensor reluctor wheel for damage or conditions
that causes misalignment.
W as any fault found and rectified? Go to Step 12 Go to Step 9
9 Replace the VSS. Refer to 7B1 Manual Transmission – V6.
W as the repair completed? Go to Step 12 —
10 Test the VSS signal circuit for a high resistance, open circuit, short to
ground or short to voltage fault condition. Refer to 8A Electrical -
Body and Chassis for information on electrical fault diagnosis.
W as any fault found and rectified? Go to Step 12 Go to Step 11
11 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 12 —
12 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Does DTC P0500 fail this ignition cycle? Go to Step 2 Go to Step 13

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Engine Management – V6 – Diagnostics Page 6C1-2–135

Step Action Yes No
10 1 Repair the high resistance or open circuit fault condition in the
voltage circuit of the cruise control cancel switch. Refer to 8A
Electrical - Body and Chassis for information on electrical wiring
repair procedures.
W as the repair completed? Go to Step 14 —
11 1 Test the cruise control cancel switch. Refer to 8C Cruise Control
– HFV6.
W as any fault found and rectified? Go to Step 14 Go to Step 12
12 1 Test the control circuits of the cruise control cancel switch for a
high resistance, open circuit, short to ground or short to voltage
fault condition. Refer to 8A Electrical - Body and Chassis for
information on electrical fault diagnosis.
W as the repair completed? Go to Step 14 Go to Step 13
13 1 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 14 —
14 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Does DTC P0504 or P571 fail this ignition cycle? Go to Step 2 Go to Step 2
15 1 Using Tech 2, select the DTC display function.
Are there any DTCs displayed? Go to the
appropriate DTC
Table in this Section System OK
When all diagnosis and repairs are completed, check the system for correct operation.
7.29 DTC P0506, P0507, P0638, P1551, P2100,
P2101, P2119 or P2176
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0506 – Idle Speed Control rpm Too Low
• DTC P0507 – Idle Speed Control rpm Too High
• DTC P0638 – Commanded Versus Actual Throttle Position Correlation
• DTC P1551 – Throttle Control Lower Position Not Reached During Learning Mode
• DTC P2100 – Throttle Control Motor Malfunction
• DTC P2101 – Throttle Control Position Range / Performance
• DTC P2119 – Closed Throttle Position Range / Performance
• DTC P2176 – Throttle Control Lower Position not Learned
Circuit Description
The ECM monitors and evaluates the accelerator pedal position (APP) sensors signal voltage along with other sensor
inputs to determine the desired throttle opening. To control the throttle plate movement, the ECM applies a pulse width
modulated (PW M) signal voltage to the throttle actuator motor through the throttle actuator motor control circuits.
• At engine idle speed or when no current is flowing into the throttle actuator motor, a constant force return spring
holds the throttle plate at a constant seven percent throttle opening position.

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Engine Management – V6 – Diagnostics Page 6C1-2–138

P0506, P0507, P0638, P1551, P2100, P2101, P2119 or P2176 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2 Refer to
4.4 Diagnostic
System Check in this Section
2 1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for running the DTC.
3 Start the engine.
4 Quickly depress the accelerator pedal to wide-open throttle then release pedal. Repeat this procedure several times.
5 Using Tech 2, select the DTC display function.
Does DTC P0506, P0507, P0638, P1551, P2100, P2101, P2119 or
P2176 fail this ignition cycle? Go to Step 3 Refer to Additional
Information in this DTC
3 Is DTC P0121, P0122, P0123, P0221, P0222 or P0223 also set? Go to the
appropriate DTC table. Go to Step 4
4 1 Disconnect the throttle actuator wiring connector.

Accidental operation of the TAC motor while
performing throttle plate inspection may cause severe
personal injury. Refer to 6C1-3 Engine Management –
V6 – Service Operations for additional precautions on
throttle body service procedure.
2 Inspect the throttle plate for the following:
• excessive dirt build-up in the throttle body,
• not in rest position,
• binding open or binding close,
• binding when moving from open to close or close to open
position, and
• free to move open or close without spring pressure.
W as any fault found and rectified? Go to Step 13 Go to Step 5
5 Inspect the engine for fault conditions that causes incorrect idle
speed. Refer to 5.12 Rough, Unstable, Incorrect Idle or Stalling in
this Section.
W as any fault found and rectified? Go to Step 13 Go to Step 6
6 1 Switch on the ignition with the engine not running.
2 Using a digital multimeter, measure the voltage between the TAC positive circuit and the ECM housing.
Does the multimeter display 2 – 4 V? Go to Step 7 Go to Step 9
7 1 Switch on the ignition with the engine not running.
2 Using a digital multimeter, measure the voltage between the TAC negative control circuit and the ECM housing.
Does the multimeter display 2 – 4 V? Go to Step 8 Go to Step 9

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Engine Management – V6 – Diagnostics Page 6C1-2–139

Step Action Yes
No
8 1 Switch off the ignition.
2 Connect Tool No. J34730-405 injector test lamp between the positive and negative control circuit of the TAC.
3 Switch on the ignition for about 5 seconds then switch off while observing the test lamp.
Does the test lamp illuminate briefly each time the ignition cycles? Go to Step 11 Go to Step 10
9 Test the TAC control circuit that measured outside the specified value
for a high resistance, open circuit, short to ground or short to voltage
fault condition. Refer to 8A Electrical - Body and Chassis for
information on electrical fault diagnosis.
W as any fault found and rectified? Go to Step 13 Go to Step 12
10 Test the positive and negative control circuits of the TAC for a shorted
together fault condition. Refer to 8A Electrical - Body and Chassis for
information on electrical fault diagnosis.
W as any fault found and rectified? Go to Step 13 Go to Step 12
11 Replace the throttle body assembly. Refer to 6C1-3 Engine
Management – V6 – Service Operations.
W as the repair completed? Go to Step 13 —
12 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 13 —
13 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Does any of the TAC motor control circuit DTCs fail this ignition
cycle? Go to Step 2 Go to Step 14
14 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs? Go to the
appropriate DTC
Table in this Section System OK
When all diagnosis and repairs are completed, check the system for correct operation.
7.30 DTC P0513, P0633, P1629, P1632, P1677,
P1678 or P1679
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0513 – W rong Transponder Key
• DTC P0633 – Immobiliser Function Not Programmed
• DTC P1629 – Immobiliser Fuel Enable Signal Not Received
• DTC P1632 – Immobiliser Fuel Disable Signal Received
• DTC P1677 – Immobiliser Function Not Enabled
• DTC P1678 – Engine Control Module Identification Failed
• DTC P1679 – Immobiliser Environment Identification Failed

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Engine Management – V6 – Diagnostics Page 6C1-2–144

Step Action
Yes No
8 1 Disconnect the ECM wiring connector.
2 Test the EOP sensor low reference circuit for a high resistance and open circuit fault condition. Refer to 8A Electrical - Body
and Chassis for information on electrical fault diagnosis.
NOTE
The EOP sensor shares the low reference circuit with
other sensors. A fault condition in the low reference circuit
may trigger DTCs on sensors that share this circuit. Refer
to 3 W iring Diagrams and Connector Charts in this
Section, to assist diagnosis.
W as any fault found and rectified? Go to Step 11 Go to Step 10
9 Replace the EOP sensor. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 11 —
10 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 11 —
11 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Does any of the for the engine oil pressure sensor circuit DTCs s fail
this ignition cycle? Go to Step 2 Go to Step 12
12 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs? Go to the
appropriate DTC
Table in this Section System OK
When all diagnosis and repairs are completed, check the system for correct operation.
7.32 DTC P0532 or P0533
DTC Descriptors
This diagnostic procedure supports the following DTCs:
• DTC P0532 – A/C Pressure Sensor Voltage Low
• DTC P0533 – A/C Pressure Sensor Voltage High
Circuit Description
The ECM supplies a positive 5 V reference voltage to the air-conditioning (A/C) refrigerant pressure sensor through
reference circuit and the ground through the low reference circuit.
The A/C pressure sensor provides signal voltage to the ECM through the signal circuit that is proportional to the A/C
refrigerant pressure. The ECM monitors the signal voltage of the A/C pressure sensor to determine the refrigerant
pressure.
• The A/C pressure sensor voltage increases as the refrigerant pressure increases.
• W hen the ECM detects the refrigerant pressure exceeds a predetermined value, the ECM activates the cooling
fans to reduce the refrigerant pressure.
• W hen the ECM detects the refrigerant pressure is too high or too low, the ECM disables the A/C clutch to protect
the A/C compressor from damage.

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Engine Management – V6 – Diagnostics Page 6C1-2–146

Step Action Yes No
3 1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P0532 or P0533 fail this ignition cycle? Go to Step 4 Refer to Additional
Information in this DTC
4 1 Switch off the ignition.
2 Disconnect the A/C pressure sensor connector.
3 Switch on the ignition with the engine not running.
4 Using a digital multimeter, measure the voltage between the A/C pressure sensor 5 V reference circuit and the ECM housing.
Does the multimeter display 4.8 – 5.2 V? Go to Step 5 Go to Step 7
5 1 Connect a 3 A fused jumper wire between the A/C pressure
sensor 5 V reference circuit and signal circuit.
2 Switch on the ignition with the engine not running.
3 Using Tech 2, observe the ECM A/C pressure voltage parameter.
Does Tech 2 display 4.8 – 5.2 V?
Go to Step 6 Go to Step 8
6 1 Switch off the ignition.
2 Remove ECM Fuse 29 from the engine compartment fuse and relay panel assembly.
3 Using a digital multimeter, measure the resistance between the A/C refrigerant pressure low reference circuit and the ECM
housing.
NOTE
Install the ECM Fuse 29 to the engine compartment fuse
and relay panel assembly after completing the test.
Does the multimeter display 5 Ω? Go to Step 10 Go to Step 9
7 Test the A/C pressure sensor 5 V reference circuit for a high
resistance, open circuit, short to ground, or short to voltage fault
condition. Refer to 8A Electrical - Body and Chassis for information on
electrical fault diagnosis.
W as any fault found and rectified? Go to Step 12 Go to Step 11
8 Test the A/C pressure sensor signal circuit for a high resistance, open
circuit, short to ground, or short to voltage fault condition. Refer to 8A
Electrical - Body and Chassis for information on electrical fault
diagnosis.
W as any fault found and rectified? Go to Step 12 Go to Step 11
9 Test the A/C pressure sensor low reference circuit for a high
resistance or open circuit condition. Refer to 8A Electrical - Body and
Chassis for information on electrical fault diagnosis.
W as any fault found and rectified? Go to Step 12 Go to Step 11
10 Replace the A/C pressure sensor. Refer to 6C1-3 Engine
Management – V6 – Service Operations.
W as the repair completed? Go to Step 12 —
11 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 12 —

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ISUZU KB P190 2007

Engine Management – V6 – Diagnostics Page 6C1-2–148

Conditions for Clearing the DTC
The ECM system voltage DTCs are Type C DTCs. Refer to 1.4 Diagnostic Trouble Codes in this Section, for action
taken when a Type C DTC sets and conditions for clearing Type C DTCs.
Additional Information
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• Refer to 6C1-1 Engine Management – V6 – General Information for details of the ECM operation.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to 8A Electrical -
Body and Chassis for information on electrical fault diagnosis.
• To assist diagnosis, refer to 3 W iring Diagrams and Connector Charts in this Section, for the system wiring
diagram and connector charts.
DTC P0560, P0562 or P0563 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2 Refer to
4.4 Diagnostic
System Check in this Section
2 1 Switch off the ignition for 30 seconds.
2 Increase the engine speed to 1500 rpm or operate the vehicle within the conditions for running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P0560, P0562, or P0563 fail this ignition cycle? Go to Step 3 Refer to Additional
Information in this DTC
3 Test the battery condition. Refer to 6D1-3 Battery – V6.
W as any fault found and rectified? Go to Step 9 Go to Step 4
4 Test the charging system operation. Refer to 6D1-1 Charging System
– V6.
W as any fault found and rectified? Go to Step 9 Go to Step 5
5 Test all the ECM fuses. Refer to 8A Electrical - Body and Chassis.
W as any fault found and rectified? Go to Step 9 Go to Step 6
6 Check the ECM ground connections for corrosion, loose terminal or
incorrect position. Refer to 8A Electrical - Body and Chassis for
information on electrical fault diagnosis.
W as any fault found and rectified? Go to Step 9 Go to Step 7
7 Test the following circuits for a high resistance or open circuit fault
condition.
• Continuous battery supply circuit,
• switched battery supply circuit,
• ignition 1 circuit, and
• ignition 2 circuit.
Refer to 8A Electrical - Body and Chassis for information on electrical
fault diagnosis.
W as any fault found and rectified? Go to Step 9 Go to Step 8
8 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 9 —

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Engine Management – V6 – Diagnostics Page 6C1-2–150

DTC P0606
There is an internal ECM circuit fault condition for 6 seconds.
Conditions for Clearing the DTC
The ECM Internal Circuit, Programming or Memory Fault DTCs are Type A DTCs. Refer to 1.4 Diagnostic Trouble
Codes in this Section, for action taken when a Type A DTC sets and conditions for clearing Type A DTCs.
Additional Information
• Refer to 6C1-1 Engine Management – V6 – General Information for details of the ECM operation.
• Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic
procedure for shorted terminals or poor wiring connection before replacing any component. Refer to 8A Electrical -
Body and Chassis for information on electrical fault diagnosis.
• For an intermittent fault condition, refer to 5.2 Intermittent Fault Conditions in this Section.
• To assist diagnosis, refer to 3 W iring Diagrams and Connector Charts in this Section, for the system wiring
diagram and connector charts.
DTC P0601, P0602, P0604 and P0606 Diagnostic Table
Step Action Yes No
1 Has the Diagnostic System Check been performed?
Go to Step 2 Refer to
4.4 Diagnostic System Check in this Section
2 1 Switch off the ignition for 30 seconds.
2 Operate the vehicle within the conditions for running the DTC.
3 Using Tech 2, select the DTC display function.
Does DTC P0601, P0602, P0604 or P0606 fail this ignition cycle? Go to Step 3 Refer to Additional
Information in this DTC
3 Test all ECM fuses and ground connections. Refer to 8A Electrical -
Body and Chassis.
W as any fault found and rectified? Go to Step 6 Go to Step 4
4 Attempt to program the ECM.
W as the programming successful? Go to Step 6 Go to Step 5
5 Replace the ECM. Refer to 6C1-3 Engine Management – V6 –
Service Operations.
W as the repair completed? Go to Step 6 —
6 1 Using Tech 2, clear the DTCs.
2 Switch off the ignition for 30 seconds.
3 Start the engine.
4 Operate the vehicle within the conditions for running the DTC.
Does any of the ECM internal circuit, programming or memory fault
DTCs fail this ignition cycle? Go to Step 2 Go to Step 7
7 Using Tech 2, select the DTC display function.
Does Tech 2 display any DTCs? Go to the
appropriate DTC
Table in this Section System OK
When all diagnosis and repairs are completed, check the system for correct operation.

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ISUZU KB P190 2007